The present invention relates to a method for purifying marine mammal oil enriched in omega 3 fatty acids and to compositions comprising such oils. The invention also relates to a method of preparing such oils from the seal and other marine mammals. More particularly, the present invention relates to a process for the transformation of subcutaneous and muscular tissues from the seal and other marine mammals. Even more particularly, the present invention relates to a process for obtaining lipid and protein extracts from the carcasses of seal and other marine mammals and to these extracts. In addition, the invention relates to fractions obtained by the methods of the present invention and to food supplements comprising same.
Seals have been hunted for their fur and their meat for hundreds of years. Recently, these animals have been hunted mainly for their fur and blubber oil, the residual carcass often being thrown back to the sea. There is thus a often, a very significant waste of seal tissue.
The entire seal trade hopes to find a growing market for seal meat, seal fat products, and in the case of the Asian market, seal-genitalia based aphrodisiac products. A renewed interest for seal oil has recently emerged, because of the properties of seal oil extracted from the blubber which is enriched in omega-3 fatty acids. Seal oil is a typical marine, because it is enriched in omega-3 fatty acids. More specifically it contains docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) the beneficial properties of which are well known to those in the art. In addition, these oils contain considerable levels of squalene and Vitamin E. These compounds are essential to the development and the maintenance of good health. In fact, over the past twenty years, health experts have recommended diets lower in saturated fats and higher in polyunsaturated fats. While this advise has been followed by a number of consumers, the incidence of heart disease, cancer, diabetes and many other debilitating diseases has continued to increase steadily. Scientists agree that the type and source of polyunsaturated fats is as critical as the total quantity of fats. The most common polyunsaturated fats are derived from vegetable matter and are lacking in long chain fatty acids (e.g. Omega-3). In addition, the hydrogenation of polyunsaturated fats to create synthetic fats has contributed to the rise of certain health disorders and exacerbated the deficiency in some essential fatty acids. Indeed, many medical conditions have been identified as benefiting from an Omega-3 supplementation. These include acne, allergies, Alzheimer""s, arthritis, artherosclerosis, breast cysts, cancer, cystic fibrosis, diabetes, eczema, hypertension, hyperactivity, intestinal disorders, kidney dysfunction, leukemia, and multiple sclerosis. Of note, the World Health Organization has recommended that infant formulas be enriched with Omega 3 fatty acids.
The conventionally used polyunsaturates are those derived from vegetable oils, which contain significant amounts of omega 6 but little or no omega 3. While omega 6 and omega 3 fatty acids are both necessary for good health, they must be consumed in a balance of about 4:1. Today""s Western diet has created a serious imbalance with current consumption on average of 20 times more omega 6 than omega 3. Concerned consumers have begun to look for health food supplements to restore the equilibrium. The three principal sources of omega 3 are flaxseed oil, fish oils, and seal oil. The past decade has seen rapid growth in the production of flaxseed and fish oils. Both types of oil are considered good dietary sources of polyunsaturated fats but are less effective than seal oil in supplying omega 3 fatty acids. Flaxseed oil contains no EPA, DHA, or DPA but rather contains linolenic acidxe2x80x94a building block enabling the body to manufacture EPA. There is evidence however that the rate of metabolic conversion can be slow and unsteady, particularly among those with impaired health. Fish oils vary considerably in the type and level of fatty acid composition depending on the particular species and their diets. For example, fish raised by aquaculture tend to have a lower level of omega 3 fatty acids than that in the wild. Research has shown that seal oil is more beneficial to those at risk of heart disease and diabetes than is fish oil. Scientists postulate that this stems from the relative absence of DPA in fish oil and the slower rate at which the body is able to extract and utilize the EPA and DHA content of fish oil.
The richest, most direct and complete source of Omega 3 oils is found in the blubber of certain marine mammals and especially in the Harp Seal. In addition, the body""s absorption of omega 3 from seal blubber is faster and more efficient than from flaxseed and fish oils. This is due, in part, to the molecular configurations of the EPA and DHA in seal oil, which varies slightly from those found in fish oils.
Traditionally seal oil has been extracted by processes requiring high temperatures which favor oxidation of polyunsaturated fats.
Methods of the prior art which describe methods for extracting oil from marine mammals require heating. For instance, GB-A-711 352 describes a method for extracting oil from vegetable and animal material including whale liver and meat. The material is preferably heated at a temperature of around 60xc2x0 C. to 80xc2x0 C. to reduce the viscosity of the mixture and to perform two tasks: 1) enable a better extraction of the oil; and 2) obtain a better atomization of the proteins during homogenization. Similarly, XP-002164137 describes a method of extracting sperm whale fat which require heating the material to 45xc2x0 C. to 55xc2x0 C. Also, GB-A-470,223 teaches a method of extracting oil from whale blubber which require heating at 45xc2x0 C. to 55xc2x0 C.
Other methods of extracting oil from marine mammals require the use of toxic solvents. For instance, XP-002164136 describes a method of extracting oil from whales or seals comprising the use of such toxic solvents such as chloroform and methanol.
The oil of marine mammals, such as seal thus provides significant advantages. Unfortunately, simple and cost-effective processes for the purification of oil from such marine mammals have not been provided. In addition, processes enabling a purification of oil containing a significant amount of Omega 3 fatty acids, from fat tissues, active protein fractions, and lipids from muscle and visceral tissues have yet to be provided. Furthermore, in view of the significant decrease in the price of seal pelt (about 50% in the last year) and of the very low price of marine mammal carcasses (from the 1997 Newfoundland and Labrador Seafood Industry, Newfoundland Department of Fisheries and Aquaculture), there is a need to increase the value of marine mammals (seals in particular), body parts and more particularly of their carcasses.
There also remains a need to find a utility and/or interest for the proteins of the carcasses of marine mammals such as that of the seal.
In view of the reported health benefits for Omega 3-containing fatty acids, there remains a need to provide extracts containing significant quantities thereof, means to prepare same by a simple and cost-effective method and to provide food supplement comprising such extracts.
The present invention seeks to meet these and other needs.
The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety.
The invention concerns a method for obtaining and purifying a marine mammal oil enriched in omega 3 fatty acids, which overcomes the drawbacks of the prior art. More particularly, the invention concerns a process for the purification of oil enriched in omega 3 fatty acids from seal tissue, fractions comprising such oil, and food supplements comprising same. In a particular preferred embodiment, the seal tissue is the blubber, which yields a significant quantity of oil.
The present invention further relates to a process of extracting omega 3-containing fatty acids from a marine mammal, which allows the recovery of blubber oil under conditions that preserve its quality. More particularly the method of extraction of omega 3 fatty acids reduces the oxidation of polyunsaturated fats. The process further allows the recovery of lipids from other tissues as well as a protein isolate from the carcass. By using the carcass as substrate far the extraction and purification, the instant process provides a significant value addition in addition to enabling a more environment friendly disposal of carcasses and undesired tissues form marine mammals. Indeed, the present invention enables a recycling of marine mammal tissues which are often discarded.
More particularly, in one preferred embodiment, the invention relates to a process for the transformation of the seal and related species according to which the subcutaneous fat tissues thereof are extracted by xe2x80x9ccold pressurexe2x80x9d in the absence of solvent.
In a particularly preferred embodiment of the present invention, the process further comprises a second step which allows the recovery of proteins from muscles and other tissues of the seal by a solvent extraction. In an especially preferred embodiment, the solvent is chosen from acetone, alcohol, ethanol, ethyl acetate or a combination of at least two such organic solvents. The lipids extracted by the solvent or solvents extraction in this second step, are recovered by evaporation of the solvent or solvents. The process comprising the second step allows the recovery of a significantly pure protein fraction, devoid of significant levels of heavy metals or pesticides (which are not precipitated along with the proteins).
Non-limiting examples of organic solvents which can be used in accordance with the present invention are well-known in the art and include alcohol (e.g. isopropanol, propanol and the like). Of course, it is preferred to use solvents which are non-toxic to animals (such as, for example, methanol).
The term xe2x80x9canimalxe2x80x9d refers broadly to the animal kingdom and thus to mammals, fish, birds and the like.
The methods of the present invention enable the production of omega 3 enriched oil from fat tissue, the obtention of substantially pure protein fractions which have retained enzymatic activity, and lipids from muscles and visceral tissues (tissues which are traditionally thrown away).
In a number of preferred embodiments, the present invention relates to seal as the marine mammal from which the extracts or fractions are prepared.
In one embodiment of the present invention, upon killing of the marine mammal having fatty acids enriched in omega 3, the mammal is immediately bled and its skin removed. Subcutaneous fat and other fat tissues are excised and kept at very low temperatures. Preferably the temperature is between about 0xc2x0 C. and about 10xc2x0 C. and more preferably between about 0xc2x0 C. and about 4xc2x0 C. Oil is extracted by exerting a physical pressure on the fat. In a particular embodiment, the oil is extracted by grinding and by applying high pressure on the tissues (cold extraction). In such a process, the fat melts into the oil, which is then recovered by filtration or centrifugation.
In a particular embodiment, the oil is purified by conventional means such as, for example, filtration and/or centrifugation. In addition, the water in the oil can be collected along with any volatile compound therein by heating as conventionally known.
In another preferred embodiment of the present invention, the other tissues from the carcass, including viscera, are grinded and extracted with cold acetone and/or ethanol. After washing of the insoluble matter, the solvent is removed from the extracts under low pressure leaving a protein concentrate retaining some active enzymatic activities and no significant level of bacterial contamination. The solvent soluble material (lipid phase) is recovered following evaporation and separation from tissue water.
In accordance with one embodiment of the present invention, there is therefore provided a method of extracting oil enriched in omega 3 fatty acids from a marine mammal comprising a lipid extraction step which comprises a submitting of a tissue from the marine mammal to a cold pressure treatment of the tissue, whereby the cold pressure treatment enables the obtention of an oil enriched in omega 3 fatty acids and which minimizes the oxidation of polyunsaturated fats, and wherein the lipid extraction step is carried-out in the absence of an organic solvent.
In accordance with another embodiment of the present invention, there is also provided a marine mammal oil enriched in omega 3 fatty acids, obtained according to the method of the present invention.
In accordance with yet another embodiment of the present invention, there is provided a food supplement composition, comprising the marine mammal oil of the present invention, together with a suitable carrier. Suitable carriers are well-known in the art.
In accordance with another embodiment of the present invention, there is also provided a marine mammal oil enriched in omega 3 fatty acids which is devoid of traces of organic solvent.
As used herein, the designation xe2x80x9cblubber oilxe2x80x9d, or xe2x80x9cblubberxe2x80x9d as known to the person of ordinary skill denotes the subcutaneous adipose tissue.
The term xe2x80x9ccold pressurexe2x80x9d is a well-known terminology in the art which refers to exerting a physical pressure on the fat at low temperature (see above).
As used herein, the terminology xe2x80x9csignificantly pure protein fractionxe2x80x9d or the like is meant to refer to a protein fraction or protein preparation which contains at least about 90% protein, preferably at least about 95% of protein. Similarly, the terminology xe2x80x9csubstantially pure protein fractionxe2x80x9d or the like refers to a protein fraction being at least 90% pure, preferentially at least 95% pure and particularly preferably at least 99% pure.
The terminology xe2x80x9cdevoid of significant levels of heavy metals or pesticidesxe2x80x9d is meant to refer to levels of pesticides or heavy metals lower than the approved standards from regulatory branches (e.g. Health Canada [e.g. The Food and Drug Act and Regulations], the Food and Drug Administration [USA] and the like).
While the process and extracts of the instant invention are demonstrated with seal tissues, marine mammals in general, having fatty acids enriched in Omega 3, could be used in the processes of the present invention. Such marine mammals are known in the art. Non-limiting examples thereof include cetacean (e.g. whales), elephant seal, seals, walrus and the like. It shall thus be understood, that the person of ordinary skill, will be able to adapt the teachings of the present invention to prepare oils, proteins and lipids from such marine mammals.
In a preferred embodiment of the instant invention, the marine mammal having fatty acids enriched in Omega 3 is the seal. The term xe2x80x9csealxe2x80x9d is used herein broadly to refer to a number of species. Non-limiting examples of species present in the Atlantic ocean include, the Harp Seal, the Hooded Seal (Cystophora cristata), the Ringed Seal (Pusa hispida), the Harbor Seal (Phoca vitulina, also found in the Pacific Ocean), the Grey Seal (Halichoerus grypus), and the Bearded Seal (Erignathus barbatus).
Of note, health experts have concluded that 80% of all Americans exhibit a deficiency in essential fatty acids. Some signs and symptoms typical but not exclusive to a deficiency in essential fatty acids are fatigue, depression, dry skin and hair, dry mucous membranes, cracked nails, indigestion, constipation and lack of endurance. Long term deficiency is associated with a higher risk of chronic degenerative diseases. As many as 60 medical conditions are linked to this deficiency or alternatively have been identified as benefiting from Omega-3 supplementation. These include acne, allergies, Alzheimer""s, arthritis, artherosclerosis, breast cysts, cancer, cystic fibrosis, diabetes, eczema, hypertension, hyperactivity, intestinal disorders, kidney dysfunction, leukemia, multiple sclerosis, myopathy, obesity, psoriasis, and vascular disease. Seal oil is proven to lower serum cholesterol without the side effects associated with prescription drugs and its ability to reduce platelets in the blood can serve as an alternative to aspirin in the prevention of stroke. The methods of the present invention and the fractions obtained thereby therefore find utility in a large number of deficiencies or disorders. The three most important of the long chain fatty acids are EPA, DHA, and DPA. These fatty acids have emerged from relative obscurity in the medical world to become one of the most important and fastest growing health supplements on the market today.
The present invention therefore also relates to compositions comprising one or more fraction in accordance with the present invention, to treat and/or protect against one or more of the deficiencies or conditions for which an omega 3 supplement is indicated and more particularly the deficiencies or conditions described above.
For administration to humans or other animals, the professional (medical professional or health food supplement expert) will ultimately determine the appropriate form and dosage for a given subject, and this can be expected to vary according to the chosen therapeutic or preventive, the response and condition of the subject, as well as the severity of the disease or conditions.
Composition within the scope of the present invention should contain the active agent (e.g. the oil enriched in omega 3 fatty acids) in an amount effective to achieve the desired therapeutic and/or preventive effect while avoiding adverse side effects. Since the oil of the present invention has a moderate to low level of vitamin A, high doses thereof can be administered (more than 100 ml). Of note, Eskimos are known to eat huge amounts of blubber, the equivalent of 250-500 ml of the oil in accordance with the present invention. Typically, the oil in accordance with the present invention can thus be administered to mammals (e.g. humans) in doses ranging from 2-10 ml daily of the oil in accordance with the present invention (based on an average person of 150 lbs.). Pharmaceutically acceptable preparations are within the scope of the present invention and are well known in the art (Remington""s Pharmaceutical Science, 16th Ed., Mack Ed.). The protein fraction in accordance with the present invention can be used as a source of protein for fish, birds or mammals for example.